Identify Your Heating Problem
When your heating system acts up, the symptoms it displays can tell you a lot about what is going wrong. This guide helps Greater Vancouver homeowners identify common heating problems based on the symptoms their system is showing. While some issues can be resolved with simple maintenance, others require professional diagnosis and repair. Use this guide to understand what you are experiencing and determine whether emergency service is needed.
No Heat or Insufficient Heat
If your furnace, boiler, or heat pump is running but not producing enough heat, several possible causes exist. The thermostat may be set incorrectly, the air filter may be severely clogged, or the system may have a mechanical issue. For furnaces, common causes include a dirty flame sensor, failed ignitor, gas valve malfunction, or blower motor problem. For boilers, low water pressure, air locked zones, or a failed circulation pump can prevent heat delivery. For heat pumps, low refrigerant charge, a frozen outdoor unit, or a stuck reversing valve can reduce heating output. If your system is blowing cold air or running constantly without satisfying the thermostat, professional diagnosis is recommended.
Unusual Noises from Your Heating System
Different sounds indicate different problems. Banging or booming sounds from a furnace often indicate a delayed ignition where gas accumulates before igniting. Screeching or squealing suggests a blower motor bearing failure or a worn belt. Rattling may indicate loose panels or ductwork issues. Kettling or rumbling from a boiler suggests limescale buildup on the heat exchanger, while gurgling sounds indicate trapped air in the system. Clicking sounds from any system usually indicate a failing ignitor or relay. Popping from a water heater indicates sediment buildup. If you hear unusual sounds, note the location and type of sound to help the technician diagnose the problem.
System Short Cycling or Frequent Cycling
Short cycling occurs when your heating system turns on and off more frequently than normal without completing a full heating cycle. This wastes energy, increases wear on components, and reduces comfort. Common causes include a dirty air filter restricting airflow, an oversized system that heats the space too quickly, a malfunctioning thermostat located in a drafty area, or safety limit switches that are tripping prematurely. For boilers, short cycling can also be caused by an oversized boiler relative to the system demand or by air in the system causing false temperature readings at the sensor.
Odd Smells: Gas, Burning, or Musty Odours
Different smells have different meanings and urgency levels. A gas odour requires immediate evacuation and a call to the gas utility from outside. A burning smell when the system first starts up in the fall is often normal dust burning off the heat exchanger, but if it persists or is accompanied by smoke, turn off the system and call for service. A musty smell can indicate mould growth in ductwork or a condensate drain issue. A metallic or oily smell from a boiler may indicate a coolant leak. Rotten egg smell specifically indicates a natural gas leak and must be treated as an emergency.
Safety Reminder
If you smell gas, suspect carbon monoxide or believe there is an immediate danger, leave the property and contact emergency services or the appropriate gas emergency authority. Do not remain inside — exit the building immediately and call for help from outside.